Purchased mine new and it is still running with 165,000 miles on it. Drove it HARD everyday for nearly six years without doing much more than changing the oil (and didn't do that very often), i.e it has survived use and abuse. Only complaint is the fuel pump which started to give me trouble at about 125,000 miles and is the reason why I'm no longer driving it (but I am now driving a 2005 model if that gives any indication about the significance).
Overall size - not too big, not too small, just right.
Do something about the fuel pump! I know several explorer owners who have had similar experiences.